The first part of a new series of tutorials on developing for UIQ is now available on the Sony Ericsson Developer world website. The tutorials  are written by freelance developer Simon Judge and part 1 covers cover UIQ the platform and offers an architectural overview.

From the Sony Ericsson website: 

The market for applications based on the UIQ 3 software platform is growing fast with an increasing number of people using a Sony Ericsson UIQ-3 based phone as their main tool for personal and enterprise productivity. To help get application developers up-to-speed, we are adding to our existing range of developer tutorials a new series covering all aspects of creating apps for the UIQ 3 platform and Sony Ericsson's UIQ 3-based phones.

In part 1 he describes what UIQ is, where it fits in the Symbian OS ecosystem, why you should develop for it and the fundamentals of designing a new UIQ 3 application.